Rokka works part-time at Live House Galaxy. She also works and lives at her relatives' bathhouse.
Ever since she was at elementary school, she failed at everything, including studies, that she had tried. Playing guitar was the only thing she had worked hard at. And because of that, she had formed a band with fellow schoolmates TRICK, Berry, and Pat (all are monikers).
Her father was at first against her decision to study at Tokyo but she persuaded him by finding a place to live at Tokyo and finding a school that offers a scholarship for a cheaper tuition fee than that of her local high school. She promised him that she'll study hard. After that, her father told her if that is all that she can do, she should just give up and talk again later when she can do house chores. Her mother offered to teach her. However, her father allowed her to do whatever she wanted after he saw how hardworking Rokka is. She later passed Haneoka High School's entrance exam and finally be able to do household chores.
Her middle school band disbanded when Rokka went to study at Tokyo after performing one last song together to celebrate Rokka's 'fresh start'.
Rokka also has a cousin named Nanami. She offered to let Rokka stay in her room when the latter decided to study in Tokyo.
Rokka is a slender girl of average height. She has sharp leafy green eyes and blue hair with her fringe splitting into three sections and her bangs reach her chins. The rest of her hair is resting on a shoulder-laying with a thick scrunchy with star ornaments.
She wears black glasses and wears a frilly dress with a bow behind with green socks and two strap flat brown shoes. Her necklace carries a key to her house.
When she performs, she takes both her glasses and scrunchy off. She also used to style her hair into two ponytails, and switched to a side plait with a starry scrunchy when she departed Gifu after her graduation.
- In the second season of the anime, LOCK is introduced as a deuteragonist, and follows her quest to create or join a band.
- She made her first appearance in BanG Dream! Girls Band Party! during the Determined Darkness, Blue Rose Pride event.
- She worked hard to buy her guitar.
- Her backstory is told in RAiSe! The story of my music chapters 1-4.
- Her birthday, July 17, is the same date when THE THIRD 2nd Live was held.